The present invention generally relates to multichamber containers having a selectively openable seal line between two chambers. More particularly, the invention relates to dual chamber bags for delivery of medical substances to a patient, e.g., via an administration set.
In the medical field it is often necessary to mix two separate components such as a drug into a diluent or a dextrose and amino acids. The components of such mixtures must often be stored separately. In the case of amino acids and dextrose, for example, the mixture is not stable over long periods of time. Such instability may also be true for the mixture of a drug in a diluent. Also, some drugs lose their efficacy when stored in a liquid diluent and must be stored in a powdered form and reconstituted prior to use.
Due to the characteristics of the different components, it may be necessary to sterilize the components separately, therefore the components may be combined only after each component is separately sterilized. For example, some liquid diluents, such as sterile water, are sterilized by steam sterilization, or autoclaving. The heat generated during such sterilization procedure may destroy the efficacy of many powdered drugs which, by necessity, should be sterilized by other means.
Although it is possible to separately store two components, it is desireable to quickly and easily mix the components in a closed system under sterile conditions.
It is known to provide a multiple chamber container of flexible plastic sheets having heat seal dividing the container into two or chambers. Such a container is disclosed, for example, in U.S. Pat. Nos. 4,396,388; 4,770,295; 3,950,158; 4,000,996; and 4,226,330.
In U.S. Pat. No. 4,396,488, there is disclosed a container which employs frangible valves between the heat seal to allow for selective communication and mixing between the two components stored in the two chambers.
However, it is desirable to provided a multiple chamber closed system which does not require additional elements integrated into the container to form the openable valve between the compartments. In each of U.S. Pat. Nos. 3,950,158; 4,000,996; and 4,226,330, there is disclosed a multiple chamber container which has a line of weakness, such as a score line and plastic material, which breaks upon the application of pressure.
In U.S. Pat. No. 4,770,295, a selectively open seal line is positioned between two sheets of flexible thermoplastic material, the seal line being exceptionally resistent to unintentional opening forces but easily opening upon application of a specific force. It is disclosed that the seal line may be employed in various containers, including a two chamber container for the separate storage and selective mixing of two medical substances. The container includes two sheets forming the exterior of the container and an inner diaphragm sheet between the outer sheets. One selectively openable seal is disposed between one of the outer sheets and diaphragm sheet. Preferably, a permanent line of securement is also included between the other exterior sheet and the inner diaphragm sheet extending substantially parallel to and coextensive with the openable seal line.
Tear tabs or tear strips for plastic packaging are also known, such as shown in U.S. Pat. No. 2,991,000. Such tear tabs provide ready access to the contents of a container but also involve the use of a relatively complicated seal structure. U.S. Pat. No. 3,983,994 discloses a peelable seal broken by pulling upon tabs located outside of the container.
Rupturable seal lines such as shown in the above-named patents may suffer from what is regarded as pooling of solution when the rupturable seal line is broken. In such a case, not all of the substance in one of the containers mixes with the other substance because it is captured within pockets defined by the rupturable seal line.
Further, it is desirable to provide for inspection of the seal line for leaks.